The Cataclysm not only caused immediate devastation and the tides, it weakened the working of magic. Permanent magic that had worked for millenia, such as the Dwaro magic that held up their deep caverns mostly failed, as did the magic in artifacts, weapons, even the common household magic of the later empire. To this day, permanent items can degrade or even fail without warning. Spells casting works mostly as it did in the past but casters now require Focus Items for full effect.